I have a scenario where i need to perform a gracefull shutdown on Jboss server 7 where my application needs to flush out all Objects from My application with proper logging and deleting out all the active session containing in my application . I am using spring 3.0 is there any thing provided by spring framework for this
You could implement an ApplicationListener or use a servlet context lifecycle listener instead:
Application context event handling
Servlet context event handling
Related
Is there a way in spring boot to control the graceful shutdown of the app.
I know that you can have #PreDestroy methods in beans but how can you control the ordering in which those #PreDestroy methods are called.
You can have multiple beans depending on each other will the shutdown of the context look for this dependency already and call the #PreDestroy methods in the right order or not?
For example what I would like to accomplish is:
1.) stop listening for new requests on rest endpoints
2.) prevent rabbit message listeners to accept new messages
3.) wait for all processing that has started before the shutdown but is not finished yet.
Spring-boot-2-3-0 has added support for graceful shutdown.
you can enable graceful shutdown by setting up server.shutdown=graceful property
To configure the timeout period you can use
spring.lifecycle.timeout-per-shutdown-phase=20s
spring boot documentation
If you can not upgrade to spring boot 2.3 then you can check below project
https://github.com/gesellix/graceful-shutdown-spring-boot
I have a Spring servlet called with load-on-startup = 1 and it requires a database connection, but sometimes, connection is null and the appLoader servlet fails. The connection is null because tomcat didn't had the time to load the global resources properly.
Question : How do I ask Spring to wait for jndi proper loading? I mean, order it in some way.
Dirty solution : Make another servlet with active wait and waiting for a working connection before calling my appLoader...
1) The job of <load-on-startup> is to start a servlet at the time of deployment. It just initiates(starts) the process after that it has no control over that servlet.
The entire control of the started servlet is in the hands of the web container.
The behaviour of the web container can be programmatically controlled using Event Handling mechanism.
2) Events are basically occurrence of something. Changing the state of an object is known as an event.
2.1) You can handle the events of web container using event listeners of servlet and perform some important tasks such as creating tables of the database, creating database connection object etc. at time of deploying the project.
There are many Event classes and Listener interfaces in the javax.servlet and javax.servlet.http package.
You can use ServletContextListener to store the connection object in the context attribute and later fetch that connection object from servlet context.
Here are few examples where database connection object is stored in servlet context. example1 example2 example3
2.2) You can use Event Handling mechanism of spring framework.
In spring you can poll your database connection using ContextStartedEvent that is raised when an ApplicationContext gets started.
Here, are some spring events with example.
I'm trying to implement a graceful shutdown sequence for my Spring Boot application. For that I registered a custom shutdown hook with Runtime and disabled the one provided by Spring (SpringApplication.setRegisterShutdownHook(false)). From this custom shutdown hook I first would like to pause embedded Tomcat or the connectors and some other schedulers after which I manually invoke applicationContext.close() to shutdown the rest of the Spring application.
What is the best way to get access to the embedded Tomcat instance? I was fiddling around with TomcatEmbeddedServletContainerFactory but this does not seem to give me access to default connectors or EmbeddedServletContainer which has a stop method.
You can access the EmbeddedServletContainer from the EmbeddedWebApplicationContext (just inject that) and downcast it.
i saw some code use ShutdownHook like this
Runtime.getRuntime().addShutdownHook(new Thread(){
ConfigurableApplicationContext.stop();
//close spring context;
threadpool.shutdownnow();
//close theadpool
});
is there anything useful to do like this?
i thought
when jvm exit ,maybe thread will be shutdown immediately
and spring context will close tooï¼›
what shall we do next when we need to call System.exit() ?
It really depends on your application and the lifecycle of your objects and those threads you appear to have outside of your context. If you are running the spring container inside a standalone java process, then trapping the shutdown hook like this is one way to do that. Another way is to have it listen on a tcp port and send a command to begin the shutdown process. If you are running in a web container like tomcat, then you should follow the standards on normal webapp shutdown, which Spring supports with Context Listeners.
I would also consider redesigning your app so that the threads are all managed with a bean that lives inside your spring container. For instance using a bean that is configured with directives (attributes) for start/stop methods and then that bean would use an Executor for thread pooling. This way, your shutdown is ONLY shutting down the Spring container, and Spring provides very good support for orderly shutdown of beans. One of those beans is your object holding the threads within the Executor. Its a much cleaner way than trying to integrate Spring beans with external threads.
Hope this helps.
I have a Java EE application (actually, it is an apache camel application) deployed on WebSphere Application Server 7.
My application consumes service requests from Web Services (threads started from the servlet container in WAS) and from JMS queues (not SI-BUS, but WebSphere MQ if that matters). For the JMS listener, Camel (or the underlying spring framework perhaps) initiates own threads (seems to be simple java threads more or less) to deal with JMS requests.
I also have a transactional Database attached to the application. So, in spring, I have something like this definied to grab a transaction manager (WebSphere built in JTA probably).
<tx:annotation-driven/>
So my problem is, that I get an error like this when a Camel/JMS is triggering an event in the application:
org.apache.openjpa.persistence.PersistenceException: TransactionManager not found in JNDI under name java:comp/websphere/ExtendedJTATransaction
Seems like threads not initiated by the container itself cannot do JNDI lookups correct. Is there a way around this issue?